Abstract In recent years, chaotic secure communication systems have attracted significant interest due to their higher unpredictability over conventional secure communications systems and simplicity of implementation. This study presents the modeling of four chaotic modulation techniques. The techniques are Chaotic Masking (CM), Chaos Shift Keying (CSK), Chaos On-Off Keying (COOK), and Differential Chaos Shift Keying (DCSK). Simulations were carried out using Simulink in Matlab environment to...
ABSTRACT A continuous flow multi-stage grinder for grinding grains and other applicable food products comprises the Hooper(001) which receives the grain of food item to be milled and channels it to the mill housing (002) to be milled in stages. The conveyor(003) carries the milled product from one stage of grinding to the next. Contained in the mill house at every stage the grinding pIates (004). The finally ground product comes out for collection through the discharge Channel (005). Grinding...
ABSTRACT In this work, a comparative analysis of alternative energy sources has been carried out to ascertain their suitability in terms of availability, cost, advantages and disadvantages among other factors. The selected energy alternatives are solar and inverters. The first case study-site was an office suit located in government reserved area and the second a medium house unit within Lagos the most commercial city in Nigeria. Practical surveys and data collection were carried out for the ...
ABSTRACT The properties of cast iron grade GL 250 are dependent on the microstructures developed during casting. These microstructures are in turn dependent on the composition of the alloy, type of mould and other numerous casting practice variables such as shake-out time, pouring temperature, mould ambient conditions and inoculating technique. In this work, the effect of silicon content and shake-out time on the grain size (GS) and hardness properties of GL 250 cast iron was studied using a ...
ABSTRACT In this study, the combinatorial problem of university course timetabling of an Engineering Faculty of a Nigerian university (the University of Ibadan) was addressed. The problem of assigning lecturers, rooms, and courses to fixed timeslots, normally, a week, while satisfying a number of problem-specific constraints was modeled as an Integer Linear Programming (ILP) The problem constraints have been divided into hard constraints and soft constraints. While the hard constraints consti...
Abstract In this work, three models are used to analyze the electric load capacity of a fast growing urban city and to estimate its future consumption. Ikorodu, the case-study location is a highly populated city whose energy demand is continuously increasing. The ultimate focus of this study is to establish a basis for the comparison of different electric load consumption for texisting populace and to provide estimates for the future planning of the city. In this work, three different models...
ABSTRACT Rice is the edible seed of a plant which is a member of the grass family. It is an annual plant which is grown in many countries throughout the world and is the staple diet for over half the world's population. Rice milling firm has therefore occupied a significant position in the small, medium and large scale enterprises of many nations. In application of job scheduling in rice milling activities a framework for proper scheduling of activities (jobs) in rice milling processing firm ...
ABSTRACT This paper presents the evaluation of the impact of climate change on water resources and yield capacity of Asa and Kampe reservoirs. Trend analysis of mean temperature, runoff, rainfall and evapotranspiration was carried out using Mann Kendall and Sen’s slope, while runoff was modeled as a function of temperature, rainfall and evapotranspiration using Artificial Neural Networks (ANN). Rainfall and runoff exhibited positive trends at the two dam sites and their upstream while fore...
ABSTRACT Lagos State has grown from 300,000 and 500,000 in 1950 and 1991 to an unprecedented population of 15.7 million (Mabogunje, 2002). Already, it is projected to have a population of 25 million by 2015 which will make Lagos the third largest megacity after Tokyo and Bombay and a population of 29 million by 2020, with an annual growth rate of 8 %( UNCHS, 1996; George, 2010; LWC, 2011). This scenario presents enormous emerging challenges as well as opportunities that are numerous, diverse...
ABSTRACT Energy and exergy analysis was conducted for a vegetable oil refinery in the Southwest of Nigeria. The plant, powered by two boilers and a 500 kVA generator, refines 100 tonnes of crude palm kernel oil (CPKO) into edible vegetable oil per day. The production system consists of four main group operations: neutralizer, bleacher, filter, and deodorizer. The performance of the plant was evaluated by considering energy and exergy losses of each unit operation of the production process. Th...
ABSTRACT The importance of cereal gruel as a highly nutritious food for infants in many countries in Africa cannot be overstated. Conventional methods of producing these food-slurries prior to their consumption as food cannot meet up with the high demand for these gruels. This current work is targeted at developing various archetypal machines for the improvement of the production of these food slurries. Three prototype machines have been developed and discussed in this paper, namely, the suct...
ABSTRACT Heat conduction through conventional and interlocking building bricks with cavities was studied in this work. Heat transfer analysis was carried out using MATLAB® partial differential equation toolbox. Regular and staggered hole arrangements were studied. Results showed that four staggered holed interlocking bricks were effective in thermal resistance into the bricks and increasing the holes beyond four did not give any thermal resistance advantage. For the conventional bricks stag...
ABSTRACT Experiments have been conducted to develop temper-annealing schedule for continously cast and cold-worked aluminium 1200. By using the method of graphical combination of the results of tensile and deep drawn tests, it is shown that a cost effective temper-annealing schedule that would impart improved mechanical properties.
ABSTRACT In vitro gas production of four different browse plants (Azadirachta indica, Terminalia catappa, Mangifera indica and Vernonia amygdalina) was investigated under different extractions. The relationship between the forage composition parameters (dry matter, organic matter, crude protein, acid detergent fibre, neutral detergent fibre and acid detergent lignin), process parameters (extraction mode and incubation time), and volume of gas production were modelled with artificial neural ne...
Abstract This paper examined the heat-transfer coefficients and the Nusselt number for turbulent flow for a methane-air flame occurring in cross-flow streams in an open duct. The governing equation of momentum, energy, mass fraction and radical nuclei concentration were solved in a fully coupled fashion at each control volume. The model encompasses conservation equations of gas components participating in the process and energy equation. A FORTRAN code was written with a Tridiagonal matrix s...